A generic wrapper for observing changes from a Combine Publisher - Xcode 11 GM

ObservablePublisher.swift

import Foundation
import Combine
import SwiftUI

@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
class ObservablePublisher<Output>: ObservableObject {
    var bag: [AnyCancellable] = []
    @Published public internal(set) var value: Output?

    init(erased publisher: AnyPublisher<Output, Never>) {
        publisher
            .receive(on: RunLoop.main)
            .sink { [weak self] in
                self?.value = $0
        }
        .store(in: &bag)
    }

    // Segmentation fault: 11 if this generic constructor is not `convenience`
    public convenience init<PublisherType: Publisher>
        (_ publisher: PublisherType)
        where PublisherType.Output == Output, PublisherType.Failure == Never {
            self.init(erased: publisher.eraseToAnyPublisher())
    }
}

@available(OSX 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
extension Publisher where Failure == Never {
    func observableObject() -> ObservablePublisher<Output> {
        return ObservablePublisher(self)
    }
}